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(Now-Modem 2Shets-Sheet1 W. R. ECKART & H. C. BEHR.

Hoisting Machine Brake.

No. 231,776. Patented Aug. 31,1880.

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Hoisting Machine Brake.

No. 231,776. Patented Aug. 31,1880.

(No Model.) 7

Witnesses; In rem-0m I MMM M -FETERS, PHOTO-UTMOGRAPHEH, WASHINGTON. n C

UNITED STATES PATENT Fares.

WILLIAM B. EGKART AND HANS U. BEHR, OF SAN FRANCISCO, GAL.

HOlSTlNG-IVIACHINE BRAKE.

' SPECIFICATION forming part of Letters Patent No. 231,776, dated August 31, 1880.

Application filed July 19, 1880. (N0 model.)

To all whom it may concern:

Be it known that we, WILLIAM R. EGKART and HANS O. BEHR, of the city and county of San Francisco, and State of California, have invented a Parallel Gripe-Brake for Hoisting Machinery; and we do hereby declare the following to be a full, clear, and exact description thereof.

Our invention relates to certain improvements in that class of machinery which is used for hoisting and lowering in mines and other places, but which is more especially adapted for heavy mining-work; and it consists in a novel construction and operation of the friction-brakes, by which the speed of the descendin g load is regulated, checked, or stopped at will, said brakes being adapted to move on parallel lines, so that all parts of the faces of the brake-shoes will be approached to or retracted from the drum at an equal rate of speed.

In the construction of brakes for this class of work the supporting-frames for the shoe are hinged or pivoted at points considerably at one side of the drum upon which they are to act, and they thus swing in an arc of a circle about these fixed points, so that the upper part of the shoe approaches the drum or recedes from it at a greater rate of speed than the lower part, which is nearer to the fulcrum. In consequence of this unequal movement there is an unequal pressure and an unequal wear of the shoes, which, in such large machinery, is a matter of grave importance.

Our invention is designed to overcome this diffieulty by the employment of what we term a parallel gripe-brake, which will be more completely described by reference to the accompanying drawings, in which- Figure 1 is a view of our brake out of contact with the drum. Fig. 2 shows it in contact. Fig. 3 shows the usual form of the pivoted tangent-brake.

A is the drum or wheel to which the brake is to be applied, the other parts of the hoisting machinery not being shown. B B are the brake-shoes, which are usually heavy wooden friction-blocks set in frames G, and having their faces formed in a curve having the same radius as the periphery of the wheel.

The frames 0 are either supported upon a shoe, 1), or by means of parallel-motion rods, so that the top and bottom of each frame and shoe will move to and from the wheel with equal rapidity.

E and F are levers having a short arm at right angles with a long arm, and having a fulcrum at the angle, so as to form a sort of bell-orank lever. These levers are pivoted one at the top and one at the bottom of one of the frames 0, and their long arms are united by a connecting-rod, G, so that they will. move together. The short arms project upward from the fulcrum, and connecting-rods H extend from each of these arms across, above, and below the wheel to the opposite frame, where they are united to it, as shown.

By means of a screw and set-nuts I the relative position of the brakes may be adjusted so that they will be brought into contact with the wheel by the action of the proper mechanism.

From the bottom of each of the frames 0 we have shown a rod, J, projecting toward the center, and these rods have screw-threads out upon them to receive nuts K. The rods pass through plates L, moving freely in one direction, but their motion in the opposite direction is limited by the nuts. These nuts stop the movement of the brake-shoes away from the wheel, so that if one moves back when released while the other does not the nuts K will stop this one at the proper distance, and the weight or spring will then act, through the rods H, to withdraw the other one. Various devices may be used to effect this purpose, a simple stop placed behind each of the frames answering the purpose as well as that described. In the present case we have shown a spring, M, placed beneath the lever-arm, which acts to' throw it up, and, through the connections, to throw the brakes back from the wheel, but practically the weight of the parts will be amply sufficient.

The operation of our apparatus will then be as follows: Power is applied at a suitable point and by any well-known or suitable apparatus, which may be represented in the pres ent case by the treadle upon the end of the lower lever. The action of drawing this lever down will, through the connecting-rod Gr, also draw the upper lever down. The short arms 2 saunas of these levers then act simultaneously upon the upper and the lower ends of the frames 0 by means of the connecting-rods H, and will draw them equally toward the wheel, so that the shoes are thrown into strong frictional contact with the wheel. This action takes place in exactly parallel lines both at top and bottom, and the shoes are thus caused to press upon the rim of the wheel with equal force at all points, and the friction and wear are thus equalized over the whole length of each shoe.

By this construction we are enabled to make the shoes much longer, and thus increase the frictional or gripin g surface the whole length of the shoes wear equally, and there is no loss of power or delay to true them up when unequally worn.

Having thus described our invention, what We claim as new, and desire to secure by Letters Patent, is

1. The brake-blocks B, supported in frames at each side of the wheel, and adapted to have their upper and lower ends moved to and from the wheel in parallel straight lines, so that each portion of the shoe moves over an equal distance and exerts an equal'pressure upon the wheels substantially as herein described.

2. The brakeblocks B, with their supporting-frames, mounted upon shoes 1), or equivalent devices, to allow them free movement, in combination with the bell-crank levers E F and connecting-rods G and H, whereby the brakeblocks may be moved simultaneouslyin parallel lines, substantially as herein described.

3. The brake-blocks B, supported in frames and united by connecting-rods G and H, and levers, whereby they are moved to and from the wheel simultaneously and in parallel lines, in combination with the stops K, substantially as and for the purpose herein described.

In witness whereof we have hereunto set our hands.

WILLIAM R. EGKART. HANS O. BEHR.

Witnesses:

CHAS. E. KELLY, ROLLIN P. SAXE. 

